Babies Learn Quickly While Sleeping

The brain activity of sleeping infants was measured using a network of electrodes, revealing the little ones had activity in the front parts of the brain while asleep.

Credit: Eve Vagg.

Babies can apparently learn even while asleep, a new study
reveals.

As newborns spend most of their time asleep, this newfound ability
might be crucial to rapidly adapt to the world around them and help to ensure their
survival, researchers said.

In experiments with 26 sleeping infants, each just one to
two days old, scientists played a musical tone followed by a puff of air to
their eyes 200 times over the course of a half-hour. A network of 124
electrodes stuck on the scalp and face of each baby also recorded brain
activity during the experiments.

The babies rapidly learned that they could expect a puff of
air upon hearing the tone, showing a four-fold increase on average in the
chances of tightening their eyelids in response to the sound by the end of each
session.

"It's surprising how quickly they learned — the study
took 30 minutes, but I think they actually learned this in half that
time," said researcher William Fifer, a developmental neuroscientist at
Columbia University in New York. "We knew that a baby's job is to be an information
gatherer, a data sponge, but I don't think we realized this also happens
when they're sound asleep."

Certain aspects of brain-wave activity over the frontal
parts of the babies' brains also increased significantly over time during the
experiments. This potentially reflected how the newborns were updating their
memories. In fact, past research showed that the brains of
sleeping infants were abuzz with activity in regions associated with
visual, motor and auditory processing.

In the new study, the kind of learned response with their
eyes depends on the part of the brain known as the cerebellum. In autism and dyslexia,
there are abnormalities linked with the cerebellum, suggesting this kind of
study may offer a new way to identify at-risk infants at a very early age.

"We don't have very good tools right now to assess
brain function in very early infancy, so this could prove very useful in
measuring how well the brain is developing," Fifer said. "And babies
spend so much time asleep, which fortunately could be an ideal time and state
to ask questions of their brain."

There are now a number of interesting questions that
scientists can now pursue with this research. For instance, "if the babies
learned something on day one while asleep, do they remember it on day two when
they are awake, or has it come and gone?" Fifer wondered.

Fifer and his colleagues detailed their findings online May
17 in the Proceedings of the National Academy of Sciences.

Charles Q. Choi is a contributing writer for Live Science and Space.com. He covers all things human origins and astronomy as well as physics, animals and general science topics. Charles has a Master of Arts degree from the University of Missouri-Columbia, School of Journalism and a Bachelor of Arts degree from the University of South Florida. Charles has visited every continent on Earth, drinking rancid yak butter tea in Lhasa, snorkeling with sea lions in the Galapagos and even climbing an iceberg in Antarctica.